Honeycomb structures are often used in the construction of aircraft, because they typically have high strength to weight ratios. Typically, honeycomb structures are sandwiched and bonded between opposing panels, or face-sheets, resulting in closed volumes of air within the cells of the honeycomb structures. Closed cells are susceptible to collecting moisture and do not permit airflow for venting, cooling, or heating applications. Moisture ingress may contribute to less than optimal performance of the bond between the honeycomb structure and adjacent panels, as well as separation and degradation of cells of the honeycomb structure. Unvented honeycomb structures may be difficult to process in autoclave bonding operations, which use gas pressure and/or vacuum to apply forces to the structure to achieve bonding, because pressures can build and collapse the honeycomb structure.